一种新的大气折射率剖面模型构建方法

针对现有大气折射率剖面模型中干项简化模型较多、使用中难以取舍和湿项简化模型精度较低等问题,利用某台站实测探空数据,对现有几种大气折射率剖面模型的精度进行了分析。在此基础上,基于小波聚类和EOF(经验正交函数)分析方法,构建了一个能够考虑天气特征的大气折射率剖面改进模型,并利用实测数据对其精度进行了验证。结果表明:改进模型拟合精度较现有模型精度有明显改进。其中,干项模型能够充分考虑台站本地气候特征,精度更高;湿项模型将天气类型细分为四类,比现有模型精度最大提高了约6个折射率单位。同时,改进模型天气类型划分方法较容易被非气象专业人员理解,便于此模型推广应用。

New method for constructing atmospheric refractivity profile model

It is difficult to select an optimal atmospheric dry refractivity profile model from the existing models for practical applications. As the atmospheric wet refractivity profile model has a lower precision, the demand to construct an improved model of atmospheric refractivity profile using measured sounding data based on wavelet-based clustering technology and EOF(Empirical Orthogonal Function) analysis method arises. Results showed that the improved model is more accurate than the existing models. The part of dry refractivity profile model can fully consider the local climatic features, and wet part has a higher precision (about 6 unit of atmospheric refractivity) than the existing models by subdividing weather types into four categories. Meanwhile, the weather classification method can be more easily understood by non-meteorological professionals to promote the application of the improved model.